There's nothing worse than people who think they'll make you act better by treating you like shit. Parents especially seem to get stuck in this retarded loop, like a friend I had who's mom I one day heard say to him "You failed again!?! Damnit ___, I've grounded you and grounded you, I've punished you every way I can think of, and this shit's still been going on for years! How much am I am going to have to punish you before you shape up?". Well DUH, you can't try the same thing a million times and expect a different result!

My point here is that your parents seem to be doing the same thing, they won't stop being assholes to you until you shape up, as if being an asshole to someone is going to improve your relationship with them. And maybe you should try bringing that up with your parents, or maybe first your siblings if it would be easier. It's very complicated, exactly how to approach the issue without sounding like you're making a hostile ultimatum.

Try this. Propose to your parents that you both make a list of everything that's frustrating you about the other people in your house, then exchange. You have to pre-agree that there are no wrong answers, that nobody will bitch anybody out for what they feel or how they see things. It's just to see a full list of how one sees the other, how your making each other feel, and why. Tell your mom (on the paper) that you feel like she cares way more about your other sibling, tell her that screaming at you only builds up your rage, tell her anything and everything that's on your mind about her or anybody.

Anywhoo, that's my advice, take it or leave it. Good luck to you.